Program and erase operations produce cumulative defects in oxide insulators and charge-trapping layers of Flash and other floating-gate memories, limiting the useful life of such products and rendering them largely unsuitable for applications that require frequent, unlimited write operations.
It has been demonstrated that by heating floating-gate memory cells to temperatures above the normal operating range, but below a tolerable maximum, otherwise permanently-trapped carriers may be dislodged from oxides and charge-trapping layers, in effect, annealing the defects and improving longevity.